(1) Field of the Invention
This invention relates to electrical alarms which are actuated by the presence of moisture.
(2) Description of the Prior Art
In modern homes expensive carpets are often laid above concrete floors. Also, often hot water heaters are located near the center of the house so that they are near bathrooms and the like. When leaks occur in this or other water using applicances, the water can ruin the carpets upon the floor.
Previous workers have designed alarms to detect the moisture in this and similar situations. The previous workers have suggested using an expansion material, which upon expansion, would close electrical contacts. Normally, the expansion material was in a confined space so that its expansion pushed one electrical contact against the other by compression. SHU, U.S. Pat. No. 3,562,731, ANDRESEN U.S. Pat. No. 2,423,367 and UHLIG U.S. Pat. No. 3,200,388 disclose such detectors.
Other alarm systems for the home have received extensive development. Specifically, fire and smoke alarms have been developed to respond to a change in conditions as detected to sound an alarm from a battery operated energy source.